Polarized light detecting device and fabrication methods of the same

ABSTRACT

Described herein is a device operable to detect polarized light comprising: a substrate; a first subpixel; a second subpixel adjacent to the first subpixel; a first plurality of features in the first subpixel and a second plurality of features in the second subpixel, wherein the first plurality of features extend essentially perpendicularly from the substrate and extend essentially in parallel in a first direction parallel to the substrate and the second plurality of features extend essentially perpendicularly from the substrate and extend essentially in parallel in a second direction parallel to the substrate; wherein the first direction and the second direction are different; the first plurality of features and the second plurality of features react differently to the polarized light.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/047,392, filed Mar. 14, 2011, and is related to U.S. patentapplication Ser. No. 12/204,686, filed Sep. 4, 2008 (now U.S. Pat. No.7,646,943), Ser. No. 12/648,942, filed Dec. 29, 2009 (now U.S. Pat. No.8,229,255), Ser. No. 13/556,041, filed Jul. 23, 2012, Ser. No.12/270,233, filed Nov. 13, 2008 (now U.S. Pat. No. 8,274,039), Ser. No.13/925,429, filed Jun. 24, 2013, Ser. No. 13/570,027, filed Aug. 8, 2012(now U.S. Pat. No. 8,471,190), Ser. No. 12/472,264, filed May 26, 2009(now U.S. Pat. No. 8,269,985, Ser. No. 13/621,607, filed Sep. 17, 2012(now U.S. Pat. No. 8,514,411), Ser. No. 13/971,523, filed Aug. 20, 2013(now allowed), Ser. No. 12/472,271, filed May 26, 2009 (now abandoned),Ser. No. 12/478,598, filed Jun. 4, 2009 (now U.S. Pat. No. 8,546,742),Ser. No. 14/021,672, filed Sep. 9, 2013, Ser. No. 12/573,582, filed Oct.5, 2009 (now allowed), Ser. No. 14/274,448, filed May 9, 2014, Ser. No.12/575,221, filed Oct. 7, 2009 (now U.S. Pat. No. 8,384,007), Ser. No.12/633,323, filed Dec. 8, 2009 (now U.S. Pat. No. 8,735,797), Ser. No.14/068,864, filed Oct. 31, 2013, Ser. No. 14/281,108, filed May 19,2014, Ser. No. 13/494,661, filed Jun. 12, 2012 (now U.S. Pat. No.8,754,359), Ser. No. 12/633,318, filed Dec. 8, 2009 (now U.S. Pat. No.8,519,379), Ser. No. 13/975,553, filed Aug. 26, 2013 (now U.S. Pat. No.8,710,488), U.S. Ser. No. 12/633,313, filed Dec. 8, 2009, Ser. No.12/633,305, filed Dec. 8, 2009 (now U.S. Pat. No. 8,299,472), Ser. No.13/543,556, filed Jul. 6, 2012 (now allowed), Ser. No. 12/621,497, filedNov. 19, 2009 (now abandoned), Ser. No. 12/633,297, filed Dec. 8, 2009,Ser. No. 12/982,269, filed Dec. 30, 2010, Ser. No. 12/966,573, filedDec. 13, 2010, Ser. No. 12/967,880, filed Dec. 14, 2010 (now U.S. Pat.No. 8,748,799), Ser. No. 12/966,514, filed Dec. 13, 2010, Ser. No.12/974,499, filed Dec. 21, 2010 (now U.S. Pat. No. 8,507,840), Ser. No.12/966,535, filed Dec. 13, 2010, Ser. No. 12/910,664, filed Oct. 22,2010, Ser. No. 12/945,492, filed Nov. 12, 2010, Ser. No. 13/048,635,filed Mar. 15, 2011 (now allowed), Ser. No. 13/106,851, filed May 12,2011, Ser. No. 13/288,131, filed Nov. 3, 2011, Ser. No. 14/032,166,filed Sep. 19, 2013, Ser. No. 13/543,307, filed Jul. 6, 2012, Ser. No.13/963,847, filed Aug. 9, 2013, Ser. No. 13/693,207, filed Dec. 4, 2012,and Ser. No. 61/869,727, filed Aug. 25, 2013, are each herebyincorporated by reference in their entirety.

BACKGROUND

Polarization is a property of certain types of waves that describes theorientation of their oscillations. Electromagnetic waves includingvisible light can exhibit polarization. By convention, the polarizationof light is described by specifying the orientation of the light'selectric field at a point in space over one period of the oscillation.When light travels in free space, in most cases it propagates as atransverse wave, i.e. the polarization is perpendicular to the light'sdirection of travel. In this case, the electric field may be oriented ina single direction (linear polarization), or it may rotate as the wavetravels (circular or elliptical polarization). In the latter cases, theoscillations can rotate either towards the right or towards the left inthe direction of travel. Depending on which rotation is present in agiven wave it is called the wave's chirality or handedness. Polarizationof fully polarized light can be represented by a Jones vector. The x andy components of the complex amplitude of the electric field of lighttravel along z-direction, E_(x)(t) and E_(y)(t), are represented as

$\begin{pmatrix}{E_{x}(t)} \\{E_{y}(t)}\end{pmatrix} = {{E_{0}\begin{pmatrix}{E_{0\; x}^{{({{kz} - {\omega \; t} + \varphi_{x}})}}} \\{E_{0\; y}^{{({{kz} - {\omega \; t} + \varphi_{x}})}}}\end{pmatrix}} = {E_{0}{{^{{({{kz} - {\omega \; t}})}}\begin{pmatrix}{E_{0\; x}^{\; \varphi_{x}}} \\{E_{0\; y}^{\; \varphi_{y}}}\end{pmatrix}} \cdot \begin{pmatrix}{E_{0\; x}^{\; \varphi_{x}}} \\{E_{0\; y}^{\; \varphi_{y}}}\end{pmatrix}}}}$

is the Jones vector. Polarization of light with any polarization,including unpolarized, partially polarized, and fully polarized light,can be described by the Stokes parameters, which are four mutuallyindependent parameters.

A device that can detect polarization of light, or even measure thelight's Jones vector or Stokes parameters can be useful in manyapplication.

SUMMARY

According to an embodiment, a device operable to detect polarized lightcomprises: a substrate; a first subpixel; a second subpixel adjacent tothe first subpixel; a first plurality of features in the first subpixeland a second plurality of features in the second subpixel, wherein thefirst plurality of features extend essentially perpendicularly from thesubstrate and extend essentially in parallel in a first directionparallel to the substrate and the second plurality of features extendessentially perpendicularly (i.e. at least 85°) from the substrate andextend essentially in parallel (i.e. at most 5°) in a second directionparallel to the substrate; wherein the first direction and the seconddirection are different; the first plurality of features and the secondplurality of features react differently to the polarized light. The term“polarized light” as used herein means light with polarization.

According to an embodiment, the polarized light has linear polarization,circular or elliptical polarization. “Linear polarization” as usedherein means the electric field of light is confined to a given planealong the direction of propagation of the light. “Circular polarization”as used herein means the electric field of light does not changestrength but only changes direction in a rotary type manner. “Ellipticalpolarization” as used herein means electric field of light describes anellipse in any fixed plane intersecting, and normal to, the direction ofpropagation of the light.

According to an embodiment, the first plurality of features is equallyspaced from each other.

According to an embodiment, the first plurality of features comprises atleast 2 features.

According to an embodiment, the first plurality of features has a pitchof about 0.5 micron to about 5 microns, a height of about 0.3 micron to10 microns, an aspect ratio of at least 4:1, preferably at least 10:1,or a combination thereof.

According to an embodiment, space between features of the firstplurality of features is filled with a transparent material.

According to an embodiment, each of the first plurality of featurescomprises a p-i-n diode or forms a p-i-n diode with the substrate, andwherein the p-i-n diode is functional to convert at least a portion ofthe polarized light to an electrical signal. A p-i-n diode means a diodewith a wide, lightly doped or intrinsic semiconductor region between ap-type semiconductor and an n-type semiconductor region. An intrinsicsemiconductor, also called an undoped semiconductor or i-typesemiconductor, is a substantially pure semiconductor without anysignificant dopant species present. A heavily doped semiconductor is asemiconductor with such a high doping level that the semiconductorstarts to behave electrically more like a metal than as a semiconductor.A lightly doped semiconductor is a doped semiconductor but not have adoping level as high as a heavily doped semiconductor. In a lightlydoped semiconductor, dopant atoms create individual doping levels thatcan often be considered as localized states that can donate electrons orholes by thermal promotion (or an optical transition) to the conductionor valence bands respectively. At high enough impurity concentrations(i.e. heavily doped) the individual impurity atoms may become closeenough neighbors that their doping levels merge into an impurity bandand the behavior of such a system ceases to show the typical traits of asemiconductor, e.g. its increase in conductivity with temperature.

According to an embodiment, the substrate comprises electricalcomponents configured to detect the electrical signal.

According to an embodiment, the device further comprises a firsttransparent electrode disposed on the first subpixel and electricallyconnected to each of the first plurality of features, and a secondtransparent electrode disposed on the second subpixel and electricallyconnected to each of the second plurality of features, wherein the firstand second transparent electrodes are separate. The term “transparent”as used herein means a transmittance of at least 70%.

According to an embodiment, the device further comprises a reflectivematerial deposited on areas of the substrate between features of thefirst plurality of features. A reflective material is a material with areflectance of at least 50%.

According to an embodiment, each of the first plurality of featurescomprises an intrinsic semiconductor layer or a first lightly dopedsemiconductor layer, and a heavily doped semiconductor layer; thesubstrate comprises a second lightly doped semiconductor layer; whereinthe second lightly doped semiconductor layer is an opposite type fromthe heavily doped semiconductor layer; intrinsic semiconductor layer ora first lightly doped semiconductor layer is disposed on the secondlightly doped semiconductor layer; and the heavily doped semiconductorlayer is disposed on the intrinsic semiconductor layer or the firstlightly doped semiconductor layer; wherein the heavily dopedsemiconductor layer, the intrinsic layer or the first lightly dopedsemiconductor layer, and the heavily doped semiconductor layer form ap-i-n diode. One semiconductor having an opposite type from anothersemiconductor means the former is n type if the latter is p type or, theformer is p type if the latter is n type.

According to an embodiment, each of the first plurality of featurescomprises a core of intrinsic semiconductor or lightly dopedsemiconductor, and a shell of heavily doped semiconductor; the substratecomprises a lightly doped semiconductor layer; wherein the lightly dopedsemiconductor layer is an opposite type from the shell; the core isdisposed on the lightly doped semiconductor layer; the shell isconformally disposed over the core; wherein the shell, the core and thelightly doped semiconductor layer form a p-i-n diode.

According to an embodiment, each of the first plurality of featurescomprises a core of lightly doped semiconductor, an intermediate shellof intrinsic semiconductor and an outer shell of doped semiconductor;wherein the intermediate shell is conformally disposed over the core;the outer shell is conformally disposed over the intermediate shell; theouter shell is of an opposite type from the core; wherein the outershell, the intermediate shell and the core form the p-i-n diode.

According to an embodiment, each of the first plurality of featurescomprises a first heavily doped semiconductor layer, a lightly dopedsemiconductor layer or intrinsic semiconductor layer, a second heavilydoped layer; wherein the first heavily doped semiconductor layer isdisposed on the lightly doped semiconductor layer or intrinsicsemiconductor layer; the lightly doped semiconductor layer or intrinsicsemiconductor layer is disposed on the second heavily doped layer; thefirst heavily doped layer is of an opposite type from the second heavilydoped layer; wherein the first heavily doped layer, the lightly dopedsemiconductor layer or intrinsic semiconductor layer and the secondheavily doped layer form the p-i-n diode.

According to an embodiment, a polarization detector array comprises anyof the device above, and electronic circuitry functional to detect theelectrical signal.

According to an embodiment, the electronic circuitry is furtherfunctional to calculate an interpolation of subpixels of the device,adjust a gain and/or calculate Stoke's parameters.

According to an embodiment, the device comprises a first subpixel, asecond subpixel, a third subpixel and a fourth subpixel, whereinfeatures on the second, third and fourth subpixels extend in transversedirections at 45°, 90° and −45° relative to a transverse direction inwhich features on the first subpixel extend.

According to an embodiment, a method of fabricating a device operable todetect polarized light comprising a substrate, a first subpixel, asecond subpixel adjacent to the first subpixel, a first plurality offeatures in the first subpixel and a second plurality of features in thesecond subpixel, wherein the first plurality of features extendessentially perpendicularly from the substrate and extend essentially inparallel in a first direction parallel to the substrate and the secondplurality of features extend essentially perpendicularly from thesubstrate and extend essentially in parallel in a second directionparallel to the substrate, wherein the first direction and the seconddirection are different and wherein the first plurality of features andthe second plurality of features react differently to the polarizedlight; the method comprises: lithography, ion implantation, annealing,evaporation, atomic layer deposition, chemical vapor deposition, dryetch or a combination thereof.

BRIEF DESCRIPTION OF FIGURES

FIG. 1 is a perspective view of the device according one embodiment.

FIG. 2 shows a schematic of the features in one subpixel when light withdifferent polarization impinges thereon.

FIG. 3 shows a method of fabricating the device of FIG. 1.

FIG. 4 is a perspective view of the device according one embodiment.

FIG. 5 shows a method of fabricating the device of FIG. 4.

FIG. 6 is a perspective view of the device according one embodiment.

FIG. 7 shows a method of fabricating the device of FIG. 6.

FIG. 8 is a perspective view of the device according one embodiment.

FIG. 9 shows a method of fabricating the device of FIG. 8.

FIG. 10 shows a polarization detector array with the device of FIG. 1,4, 6 or 8 integrated therein.

FIG. 11 shows a schematic of a light detector apparatus wherein thedevice of FIG. 1, 4, 6 or 8 is used as fore optics.

FIG. 12 shows a top view and a perspective view of a feature in thedevice of FIG. 1, wherein the feature has metal layers on its sidewalls.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings, which form a part thereof. In drawings, similarsymbols typically identify similar components, unless the contextdictates otherwise. The illustrate embodiments described in the detaileddescription, drawings, and Claims are not meant to be limiting. Otherembodiments may be utilized, and other changes may be made, withoutdeparting from the spirit or scope of the subject matter presented here.

This disclosure is drawn to, among other things, methods of use, methodsof fabrication, apparatuses, systems, and devices related to a deviceoperable to detect and distinguish light of different polarization.According to an embodiment, the device comprises a substrate having aplurality of regions defined thereon (hereafter referred to as“subpixels”; a group of related “subpixels” may be referred to as a“pixel”). In each subpixel, the device comprises a plurality of featuresextending essentially perpendicularly from the substrate, wherein theplurality of features also extend essentially in parallel in a directionparallel to the substrate (hereafter referred to as a “transversedirection”). The term “feature” used herein means a structure whosedimensions in a direction perpendicular to the substrate (hereafterreferred to as the “normal direction”) and in the transverse directionare substantially greater than a dimension of the structure in adirection perpendicular to both the normal direction and the transversedirection (hereafter referred to as the “thickness direction”). Afeature can have any suitable shape in a cross-section parallel to thesubstrate, such as a rectangle, an ellipse, convex-convex (i.e. like adouble-convex lens), concave-concave (i.e. like a double-concave lens),plano-convex (i.e. like a plano-convex lens), plano-concave (i.e. like aplano-concave lens). The plurality of features can be equally orunequally spaced from each other. The plurality of features in differentsubpixels are functional to react differently to light with a samepolarization. Here, the term “react” is meant to broadly encompassabsorbing, reflecting, coupling to, detecting, interacting with,converting to electrical signals, etc. The plurality of features in afirst subpixel extends in a first transverse direction; the plurality offeatures in a second subpixel extends in a second transverse direction,wherein the first and second pixels are adjacent and the firsttransverse direction is different from the second transverse direction.

FIG. 1 shows a device 10 according to one embodiment. For brevity, twosubpixels 10 a and 10 b of a substrate 110 are illustrated. The device10, however, can comprise a plurality of pixels such as more than 100,more than 1000, more than 1000000. The subpixels preferably have a pitchof about 1 micron to 100 microns (more preferably 5 microns). In each ofthe subpixels 10 a and 10 b, the device 10 comprises a plurality offeatures 100 (e.g. at least 2 features), respectively. The features 100in the subpixel 10 a and the features 100 in the subpixel 10 b extend indifferent transverse directions. The features 100 preferably have apitch (i.e. spacing between adjacent features 100 in the thicknessdirection thereof) of about 0.5 to 5 microns (further preferably about 1micron), a height (i.e. dimension in the normal direction) of about 0.3to 10 microns (further preferably about 5 micron) and an aspect ratio(i.e. ratio of a dimension in the transverse direction to a dimension inthe thickness direction) of at least 4:1, preferably at least 10:1. Eachof the features 100 forms a p-i-n diode with the substrate 110, thep-i-n diode being functional to convert at least a portion of lightimpinged thereon to an electrical signal. Each feature 100 comprises aheavily doped semiconductor layer 124 disposed on a lightly dopedsemiconductor layer or intrinsic semiconductor layer 121. The substrate110 comprises another lightly doped semiconductor layer 122 of anopposite type from the heavily doped semiconductor layer 124. Thelightly doped semiconductor layer or intrinsic semiconductor layer 121of the feature 100 is disposed on the lightly doped semiconductor layer122. The layers 121, 122 and 124 form the p-i-n diode. Space between thefeatures 100 can be filled with a transparent material. The device 10preferably further comprises electrical components configured to detectthe electrical signal from the features 100, for example, a transparentelectrode disposed on each subpixel and electrically connected to allfeatures 100 therein. The transparent electrode on each subpixelpreferably is separate from the transparent electrode on adjacentsubpixels. A reflective material can be deposited on areas of thesubstrate 110 between the features 100. The substrate 110 can have athickness in the normal direction of about 5 to 700 microns (preferably120 microns).

FIG. 2 shows a schematic of the features 100 in one subpixel when lightwith different polarization impinges thereon. For light 15 a with awavelength of about 400 nm and a linear polarization essentially in thethickness direction of the features 100, the absorptance of the features100 is about 35%. In contrast, for light 15 b with the same wavelengthas light 15 a and a linear polarization essentially in the transversedirection of the features 100, the absorptance of the features 100 isabout 95%.

FIG. 3 shows an exemplary method of fabrication of the device 10.

In step 1000, a silicon substrate 110 is provided, wherein the siliconsubstrate comprises an intrinsic layer or a lightly doped n type siliconepitaxial layer 121, a heavily doped n type layer 123 and a lightlydoped n type layer 122 sandwiched between the layers 121 and 123. Asubstrate of semiconductor material other than silicon (e.g. III-V orII-VI group compound semiconductor) can also be used.

In step 1001, a heavily doped p type layer 124 is fabricated on thelayer 121 by a method such as ion implantation and subsequent annealing.An exemplary dopant suitable for use in the ion implantation is boron orboron difluoride.

In step 1002, a resist layer 125 (e.g. a photoresist or an e-beamresist) is deposited on the heavily doped p type layer 124, by asuitable method such as spin coating.

In step 1003, a pattern is formed in the resist layer 125 using alithography technique (e.g. photolithograph or e-beam lithography) byremoving portions 126 of the resist layer 125. The heavily doped p typelayer 124 is exposed under the removed portions 126. The patterncorresponds to shapes and positions of the features 100.

In step 1004, a metal layer 125 is deposited on the resist layer 125 andthe exposed portions of the heavily doped p type layer 124, using asuitable technique such as thermal evaporation, e-beam evaporation, andsputtering. Exemplary metal suitable for use in the metal layer 125 arealuminum, gold, chromium, silver, copper, titanium, nickel or acombination thereof.

In step 1005, remainder of the resist layer 125 and portions of themetal layer 125 thereon are lift-off by a suitable technique such asplasma ashing and dissolution in a suitable solvent.

In step 1006, features 100 are formed by etching into the substrate 110using a suitable technique, such as dry etching with remainder of themetal layer 125 as etch mask, until portions of the lightly doped n typelayer 122 not directly below the remainder of the metal layer 125 areexposed. The features 100 now comprise remainder of the layers 121 and124.

In step 1007, a layer of oxide 128 (e.g. HfO₂, SiO₂, Al₂O₃) is depositedisotropically over the features 100 and exposed portions of the layer122, using suitable technique such as atomic layer deposition (ALD) andchemical vapor deposition (CVD). The layer of oxide 128 is functional topassivate surfaces of the features 100.

In step 1008, a metal layer 130 is deposited on the heavily doped n typelayer 123 using a suitable technique such as thermal evaporation, e-beamevaporation, and sputtering. Exemplary metal suitable for use in themetal layer 130 are aluminum, gold, chromium, silver, copper, titanium,nickel or a combination thereof. A rapid thermal annealing can beconducted following the deposition of the metal layer 130 to form anOhmic contact between the metal 130 and the heavily doped n type layer123.

In step 1009, a reflective layer 129 is deposited anisotropically on andbetween the features 100 such that sidewalls of the features 100 arepreferably free of the reflective layer 129. The reflective layer 129can be deposited by thermal evaporation or e-beam evaporation. Exemplarymetal suitable for use in the reflective layer 129 are aluminum, gold,chromium, silver, copper, titanium, nickel or a combination thereof.

In step 1010, a sacrificial layer 131 preferably with a refractive indexlower than that of the features 100 is deposited by spin coating orevaporation to fill space between the features 100. The sacrificiallayer 131 can be a suitable material such as polyimide or oxide.

In step 1011, the sacrificial layer 131 is planarized using a suitabletechnique such as chemical mechanical polishing (CMP) until the heavilydoped p type layer 124 of the features 100 is exposed.

In step 1012, a transparent conductive oxide (TCO) layer 132 isdeposited on the sacrificial layer 131 and the exposed heavily doped ptype layer 124 of the features 100, using a suitable method such asthermal evaporation, e-beam evaporation, and sputtering. The TCO layercan comprise one or more suitable materials such as indium tin oxide,aluminum zinc oxide, zinc indium oxide, zinc oxide and graphene.

In step 1013, another resist layer 133 is deposited on the TCO layer 132using a technique such as spin-coating. A pattern is formed in theresist layer 133 using a lithography technique (e.g. photolithograph ore-beam lithography) by removing portions 134 of the resist layer 133.The TCO layer 132 is exposed under the removed portions 134. The patterncorresponds to gaps to be made in the TCO layer 132 for electricallyseparating the TCO layer 132 into transparent electrodes for eachsubpixel.

In step 1014, the TCO layer 132 is dry etched using the resist layer 133as etch mask until portions of the sacrificial layer 131 is exposed inthe removed portions 134 of the resist layer 133.

In step 1015, remainder of the resist layer 133 is removed by plasmaashing or dissolution in a suitable solvent.

In step 1016, the sacrificial layer 131 is optionally removed by asuitable method such as wet etching. For example, polyimide can beremoved by a suitable photoresist developer. A thermal annealing (e.g.at 450° C. for 30 minutes) can be applied to form an Ohmic contactbetween the TCO layer 132 and the features 100.

FIG. 4 shows a device 20 according to one embodiment. For brevity, twosubpixels 20 a and 20 b of a substrate 210 are illustrated. The device20, however, can comprise a plurality of pixels such as more than 100,more than 1000, more than 1000000. The subpixels preferably have a pitchof about 1 micron to 100 microns (more preferably 5 microns). In each ofthe subpixels 20 a and 20 b, the device 20 comprises a plurality offeatures 200 (e.g. at least 2 features), respectively. The features 200in the subpixel 20 a and the features 200 in the subpixel 20 b extend indifferent transverse directions. The features 200 preferably have apitch (i.e. spacing between adjacent features 100 in the thicknessdirection thereof) of about 0.5 to 5 microns (further preferably about 1micron), a height (i.e. dimension in the normal direction) of about 0.3to 10 microns (further preferably about 5 micron) and an aspect ratio(i.e. ratio of a dimension in the transverse direction to a dimension inthe thickness direction) of at least 4:1, preferably at least 10:1. Eachof the features 200 forms a p-i-n diode with the substrate 210, thep-i-n diode being functional to convert at least a portion of lightimpinged thereon to an electrical signal. Each feature 200 comprises acore 221 of lightly doped semiconductor or intrinsic semiconductor, anda shell 223 of heavily doped semiconductor, the shell 223 beingconformally disposed over the core 221. The substrate 210 comprises alightly doped semiconductor layer 222 of an opposite type from the shell223. The core 221 is disposed on the lightly doped semiconductor layer222. The shell 223, core 221 and layer 222 form the the p-i-n diode.Space between the features 200 can be filled with a transparentmaterial. The device 20 preferably further comprises electricalcomponents configured to detect the electrical signal from the features200, for example, an electrode disposed between and electricallyconnected to the features 200 on each subpixel. The electrode disposedbetween the features 200 on each subpixel preferably is separate fromthe electrode disposed between the features 200 on adjacent subpixels.The electrode can also function as a reflective layer. The substrate 210can have a thickness in the normal direction of about 5 to 700 microns(preferably 120 microns).

FIG. 5 shows an exemplary method of fabrication of the device 20.

In step 2000, a silicon substrate 210 is provided, wherein the siliconsubstrate comprises an intrinsic layer or a lightly doped n type siliconepitaxial layer 221, a heavily doped n type layer 223 and a lightlydoped n type layer 222 sandwiched between the layers 221 and 223. Asubstrate of semiconductor material other than silicon (e.g. III-V orII-VI group compound semiconductor) can also be used.

In step 2001, a resist layer 225 (e.g. a photoresist or an e-beamresist) is deposited on the layer 221, by a suitable method such as spincoating.

In step 2002, a pattern is formed in the resist layer 225 using alithography technique (e.g. photolithograph or e-beam lithography) byremoving portions 226 of the resist layer 225. The layer 221 is exposedunder the removed portions 226. The pattern corresponds to shapes andpositions of the features 200.

In step 2003, a metal layer 227 is deposited on the resist layer 225 andthe exposed portions of the layer 221, using a suitable technique suchas thermal evaporation, e-beam evaporation, and sputtering. Exemplarymetal suitable for use in the metal layer 227 are aluminum, gold,chromium, silver, copper, titanium, nickel or a combination thereof.

In step 2004, remainder of the resist layer 225 and portions of themetal layer 227 thereon are lift-off by a suitable technique such asplasma ashing and dissolution in a suitable solvent.

In step 2005, features 200 are formed by etching into the substrate 210using a suitable technique, such as dry etching with remainder of themetal layer 227 as etch mask, until portions of the lightly doped n typelayer 222 not directly below the remainder of the metal layer 227 areexposed. The features 200 now comprise remainder of the layer 221.

In step 2006, remainder of the metal layer 227 is removed by a suitabletechnique such as wet etching with a suitable metal etchant.

In step 2007, a resist layer 229 (e.g. a photoresist or an e-beamresist) is deposited on the layer 222 and the features 200, by asuitable method such as spin coating. The resist layer 229 is thenpatterned using a lithography technique to expose portions of the layer222 at boundaries of the subpixels.

In step 2008, a silicon nitride or aluminum oxide layer 230 is depositedanisotropically over the exposed portions of the layer 222 and on theresist layer 229 using a suitable technique such as thermal evaporation,e-beam evaporation, and sputtering.

In step 2009, remainder of the resist layer 229 and any portions of thelayer 230 thereon are removed by plasma ashing or dissolution in asuitable solvent.

In step 2010, a p-type dopant layer 231 is deposited isotropically overthe features 200, remainder of on the layer 230, and the layer 222,using a suitable technique such as ALD or CVD. ALD is preferred. Thep-type dopant layer 231 can comprise a suitable p-type dopant such astrimethyboron, triiospropylborane, triethoxyborane, triisopropoxyborane,and a combination thereof.

In step 2011, an oxide layer 232 is deposited isotropically over thep-type dopant layer 231 using a suitable technique such as ALD or CVD.

In step 2012, a heavily doped p type layer 233 is formed by annealingthe device 20 to diffuse the p-type dopant layer 231 into the layer 222.The annealing can be done in a suitable atmosphere (e.g. argon) at about850° C. for 10 to 30 minutes.

In step 2013, the oxide layer 232 is removed by a suitable method suchas etching with buffered HF followed by washing. Now the heavily doped ptype layer 233 is exposed.

In step 2014, a layer of oxide 234 (e.g. HfO₂, SiO₂, Al₂O₃) is depositedisotropically over the layer 233 and remainder of on the layer 230,using suitable technique such as atomic layer deposition (ALD) andchemical vapor deposition (CVD). The layer of oxide 234 is functional topassivate surfaces of the layer 233.

In step 2015, a resist layer 235 (e.g. a photoresist or an e-beamresist) is deposited on the layer 234, by a suitable method such as spincoating. The resist layer 235 is then patterned using a lithographytechnique to expose portions of the layer 234.

In step 2016, exposed portions of the layer 234 is removed by a suitabletechnique such as dry etching to expose portions of the layer 233. Theresist layer 235 is then removed by ashing or dissolution in a suitablesolvent.

In step 2017, a resist layer 237 (e.g. a photoresist or an e-beamresist) is deposited on the layers 233 and 234, by a suitable methodsuch as spin coating. The resist layer 237 is then patterned using alithography technique such that only the features 200 and the layer 230remain under the resist layer 237.

In step 2018, a metal layer 239 is deposited anisotropically on andbetween the features 200 such that sidewalls of the features 200 arepreferably free of the metal layer 239. The metal layer 239 can bedeposited by thermal evaporation or e-beam evaporation. Exemplary metalsuitable for use in the metal layer 239 are aluminum, gold, chromium,silver, copper, titanium, nickel or a combination thereof. The resistlayer 237 is then removed by plasma ashing or dissolution in a suitablesolvent.

In step 2019, the device 20 is annealed under a suitable atmosphere(e.g. H₂ and N₂) at about 450° C. for about 30 minutes, such that themetal layer 239 and the exposed portions of the heavily doped p typelayer 233 form an Ohmic contact.

In step 2020, a resist layer 238 (e.g. a photoresist or an e-beamresist) is deposited on the layers 239 and 234, by a suitable methodsuch as spin coating. The resist layer 238 is then patterned using alithography technique to expose the remainder of the layer 230 and anyportion of the layer 234 thereon.

In step 2021, an oxide layer 240 is deposited anisotropically over anyportion of the layer 234 on the remainder of the layer 230, and over theresist layer 238, using a suitable technique such as thermal evaporationor e-beam evaporation. The oxide layer 240 is an electrical insulator.

In step 2022, a metal layer 241 is deposited anisotropically over theoxide layer 240, using a suitable technique such as thermal evaporationor e-beam evaporation. The metal layer 241 is optically opaque.

In step 2023, the resist layer 238 and any portions of the oxide layer240 and the metal layer 241 thereon are removed by a suitable techniquesuch as plasma ashing and dissolution in a suitable solvent.

FIG. 6 shows a device 30 according to one embodiment. For brevity, twosubpixels 30 a and 30 b of a substrate 310 are illustrated. The device30, however, can comprise a plurality of pixels such as more than 100,more than 1000, more than 1000000. The subpixels preferably have a pitchof about 1 micron to 100 microns (more preferably 5 microns). In each ofthe subpixels 30 a and 30 b, the device 30 comprises a plurality offeatures 300 (e.g. at least 2 features), respectively. The features 300in the subpixel 30 a and the features 300 in the subpixel 30 b extend indifferent transverse directions. The features 300 preferably have apitch (i.e. spacing between adjacent features 100 in the thicknessdirection thereof) of about 0.5 to 5 microns (further preferably about 1micron), a height (i.e. dimension in the normal direction) of about 0.3to 10 microns (further preferably about 5 micron) and an aspect ratio(i.e. ratio of a dimension in the transverse direction to a dimension inthe thickness direction) of at least 4:1, preferably at least 10:1. Eachof the features 300 preferably comprises a p-i-n diode, the p-i-n diodebeing functional to convert at least a portion of light impinged thereonto an electrical signal. Each feature 300 comprises a core 321 oflightly doped semiconductor, an intermediate shell 331 of intrinsicsemiconductor and an outer shell 332 of doped semiconductor. Theintermediate shell 331 is conformally disposed over the core 321. Theouter shell 332 is conformally disposed over the intermediate shell 331.The outer shell 332 is of an opposite type from the core 321. The outershell 332, the intermediate shell 331 and the core 321 form the p-i-ndiode. Space between the features 300 can be filled with a transparentmaterial. The device 20 preferably further comprises electricalcomponents configured to detect the electrical signal from the features300, for example, an electrode disposed between and electricallyconnected to the features 300 on each subpixel. The electrode disposedbetween the features 300 on each subpixel preferably is separate fromthe electrode disposed between the features 300 on adjacent subpixels.The electrode can also function as a reflective layer. The substrate 310can have a thickness in the normal direction of about 5 to 700 microns(preferably 120 microns).

FIG. 7 shows an exemplary method of fabrication of the device 30.

In step 3000, a silicon substrate 310 is provided, wherein the siliconsubstrate comprises a lightly doped n type silicon epitaxial layer 321,a heavily doped n type layer 323 and a n type layer 322 sandwichedbetween the layers 321 and 323. A substrate of semiconductor materialother than silicon (e.g. III-V or II-VI group compound semiconductor)can also be used.

In step 3001, a resist layer 325 (e.g. a photoresist or an e-beamresist) is deposited on the layer 321, by a suitable method such as spincoating.

In step 3002, a pattern is formed in the resist layer 325 using alithography technique (e.g. photolithograph or e-beam lithography) byremoving portions 326 of the resist layer 325. The layer 321 is exposedunder the removed portions 326. The pattern corresponds to shapes andpositions of the features 300.

In step 3003, a metal layer 327 is deposited on the resist layer 325 andthe exposed portions of the layer 321, using a suitable technique suchas thermal evaporation, e-beam evaporation, and sputtering. Exemplarymetal suitable for use in the metal layer 327 are aluminum, gold,chromium, silver, copper, titanium, nickel or a combination thereof.

In step 3004, remainder of the resist layer 325 and portions of themetal layer 327 thereon are lift-off by a suitable technique such asplasma ashing and dissolution in a suitable solvent.

In step 3005, features 300 are formed by etching into the substrate 310using a suitable technique, such as dry etching with remainder of themetal layer 327 as etch mask, until portions of the lightly doped n typelayer 322 not directly below the remainder of the metal layer 327 areexposed. The features 300 now comprise remainder of the layer 321.

In step 3006, remainder of the metal layer 327 is removed by a suitabletechnique such as wet etching with a suitable metal etchant.

In step 3007, a resist layer 329 (e.g. a photoresist or an e-beamresist) is deposited on the layer 322 and the features 300, by asuitable method such as spin coating. The resist layer 329 is thenpatterned using a lithography technique to expose portions of the layer322 at boundaries of the subpixels.

In step 3008, a silicon nitride or aluminum oxide layer 330 is depositedanisotropically over the exposed portions of the layer 322 and on theresist layer 329 using a suitable technique such as thermal evaporation,e-beam evaporation, and sputtering.

In step 3009, remainder of the resist layer 329 and any portions of thelayer 330 thereon are removed by plasma ashing or dissolution in asuitable solvent.

In step 3010, an intrinsic amorphous silicon (a-Si) layer 331 isdeposited isotropically over the features 300, remainder of on the layer330, and the layer 322, using a suitable technique such as ALD or CVD.ALD is preferred.

In step 3011, a p type doped a-Si layer 332 is deposited isotropicallyover the layer 331 using a suitable technique such as ALD or CVD. Thedevice 30 is then annealed in a suitable atmosphere (e.g. forming gas)at about 450° C. for about 30 minutes.

In step 3012, a resist layer 333 (e.g. a photoresist or an e-beamresist) is deposited on the layer 332, by a suitable method such as spincoating. The resist layer 333 is then patterned using a lithographytechnique to expose any portion of the layer 332 on the remainder of thelayer 330.

In step 3013, exposed portions of the layer 332 and any portion of thelayer 331 thereunder are removed by a suitable method such as dry etch,until the layer 330 is exposed.

In step 3014, the resist layer 333 is removed by plasma ashing ordissolution in a suitable solvent.

In step 3015, a resist layer 334 (e.g. a photoresist or an e-beamresist) is deposited by a suitable method such as spin coating. Theresist layer 334 is then patterned using a lithography technique suchthat only the features 300 and the layer 330 remain under the resistlayer 334.

In step 3016, a metal layer 335 is deposited anisotropically on andbetween the features 300 such that sidewalls of the features 300 arepreferably free of the metal layer 335. A metal layer 336 is depositedon the layer 323. The metal layers 335 and 336 can be deposited bythermal evaporation or e-beam evaporation. Exemplary metal suitable foruse in the metal layer 335 are aluminum, gold, chromium, silver, copper,titanium, nickel or a combination thereof.

In step 3017, the resist layer 334 and any portion of the metal layer335 thereon are removed by plasma ashing or dissolution in a suitablesolvent. The device 30 is then annealed under a suitable atmosphere(e.g. H₂ and N₂) at about 450° C. for about 30 minutes, such that themetal layers 335 and 336 form Ohmic contacts with the layer 332 and 323,respectively.

In step 3018, a resist layer 337 (e.g. a photoresist or an e-beamresist) is deposited on the layers 332 and 335, by a suitable methodsuch as spin coating. The resist layer 337 is then patterned using alithography technique to expose the remainder of the layer 330.

In step 3019, an oxide layer 338 and a metal layer 339 are sequentiallydeposited anisotropically, using a suitable technique such as thermalevaporation or e-beam evaporation. The oxide layer 338 is an electricalinsulator. The metal layer 241 is optically opaque.

In step 3020, the resist layer 337 and any portions of the oxide layer338 and the metal layer 339 thereon are removed by a suitable techniquesuch as plasma ashing and dissolution in a suitable solvent.

FIG. 8 shows a device 40 according to one embodiment. For brevity, twosubpixels 40 a and 40 b of a substrate 410 are illustrated. The device40, however, can comprise a plurality of pixels such as more than 100,more than 1000, more than 1000000. The subpixels preferably have a pitchof about 1 micron to 100 microns (more preferably 5 microns). In each ofthe subpixels 40 a and 40 b, the device 40 comprises a plurality offeatures 400 (e.g. at least 2 features), respectively. The features 400in the subpixel 40 a and the features 400 in the subpixel 40 b extend indifferent transverse directions. The features 400 preferably have apitch (i.e. spacing between adjacent features 100 in the thicknessdirection thereof) of about 0.5 to 5 microns (further preferably about 1micron), a height (i.e. dimension in the normal direction) of about 0.3to 10 microns (further preferably about 5 micron) and an aspect ratio(i.e. ratio of a dimension in the transverse direction to a dimension inthe thickness direction) of at least 4:1, preferably at least 10:1. Eachof the features 400 preferably comprises a p-i-n diode therein, thep-i-n diode being functional to convert at least a portion of lightimpinged thereon to an electrical signal, wherein the p-i-n diode isformed along the normal direction. For example, each feature 400comprises a first heavily doped semiconductor layer 435, a lightly dopedsemiconductor layer or intrinsic semiconductor layer 421, a secondheavily doped layer 424. The first heavily doped semiconductor layer 435is disposed on the lightly doped semiconductor layer or intrinsicsemiconductor layer 421. The lightly doped semiconductor layer orintrinsic semiconductor layer 421 is disposed on the second heavilydoped layer 424. The first heavily doped layer 435 is of an oppositetype from the second heavily doped layer 424. The first heavily dopedlayer 435, the lightly doped semiconductor layer or intrinsicsemiconductor layer 421 and the second heavily doped layer 424 form thep-i-n diode. Space between the features 300 can be filled with atransparent material. The features 400 preferably are bonded to thesubstrate 410. The device 40 preferably further comprises electricalcomponents configured to detect the electrical signal from the features400, for example, Readout Integrated Circuits (ROIC) in the substrate410. The ROIC can be electrically connected to the second heavily dopedlayer 424. The substrate 410 can have a thickness in the normaldirection of about 5 to 700 microns (preferably 120 microns).

FIG. 9 shows an exemplary method of fabrication of the device 40.

In step 4000, a silicon substrate 423 is provided, wherein the siliconsubstrate 423 comprises an silicon oxide layer 422 thereon and anintrinsic layer or a lightly doped p type silicon layer 421 on thesilicon oxide layer 422. A substrate of semiconductor material otherthan silicon (e.g. III-V or II-VI group compound semiconductor) can alsobe used.

In step 4001, a heavily doped n type layer 424 is fabricated on thelayer 421 by a method such as ion implantation and subsequent annealing.An exemplary dopant suitable for use in the ion implantation isphosphorous or arsenic.

In step 4002, a resist layer 425 (e.g. a photoresist or an e-beamresist) is deposited on the heavily doped n type layer 424, by asuitable method such as spin coating.

In step 4003, a pattern is formed in the resist layer 425 using alithography technique (e.g. photolithograph or e-beam lithography) byremoving portions 426 of the resist layer 425. The heavily doped n typelayer 424 is exposed under the removed portions 426. The patterncorresponds to shapes and positions of the features 400.

In step 4004, a metal layer 427 is deposited on the resist layer 425 andthe exposed portions of the heavily doped n type layer 424, using asuitable technique such as thermal evaporation, e-beam evaporation, andsputtering. Exemplary metal suitable for use in the metal layer 427 arealuminum, gold, chromium, silver, copper, titanium, nickel or acombination thereof.

In step 4005, remainder of the resist layer 425 and portions of themetal layer 427 thereon are lift-off by a suitable technique such asplasma ashing and dissolution in a suitable solvent.

In step 4006, features 400 are formed by etching into the layer 421using a suitable technique, such as dry etching with remainder of themetal layer 125 as etch mask, until portions of the silicon oxide layer422 not directly below the remainder of the metal layer 427 are exposed.The features 400 now comprise remainder of the layers 421 and 424.

In step 4007, remainder of the metal layer 427 is removed by a suitablemethod such as etching with a suitable metal etchant.

In step 4008, a metal layer 429 is deposited anisotropically on theheavily doped n type layer 424 and exposed portions of the silicon oxidelayer 422, using a suitable technique such as thermal evaporation,e-beam evaporation, and sputtering. Exemplary metal suitable for use inthe metal layer 429 are aluminum, gold, chromium, silver, copper,titanium, nickel or a combination thereof.

In step 4009, an oxide layer 428 (e.g. HfO₂, SiO₂, Al₂O₃) is depositedisotropically over the features 400 and the metal layer 429, usingsuitable technique such as atomic layer deposition (ALD) and chemicalvapor deposition (CVD). The oxide layer 428 is functional to passivatesurfaces of the features 400.

In step 4010, portions of the oxide layer 428 above the metal layer 429are removed by a suitable technique such as anisotropic dry etch. Nowthe metal layer 429 is exposed.

In step 4011, a silicide layer 430 is formed from the heavily doped ntype layer 424 and portions of the metal layer 429 thereon by annealingthe device 40. Remainder of the metal layer 429 is removed by a suitabletechnique such as etching with a suitable metal etchant.

In step 4012, a sacrificial layer 431 is deposited by pouring , spincoating or evaporation to fill space between the features 400. Thesacrificial layer 431 can be a suitable material such aspolydimethylsiloxane, polyimide or oxide.

In step 4013, the substrate using a suitable technique such as etchingwith potassium hydroxide, until the silicon oxide layer 422 is exposed.

In step 4014, a glass substrate 432 is bonded to the exposed siliconoxide layer 422, using a suitable technique such as using a UV removableglue. The glass substrate 432 can provide mechanical support.

In step 4015, the sacrificial layer is removed by a suitable method suchas wet etching. For example, polyimide can be removed by a suitablephotoresist developer.

In step 4016, the features 40 are bonded to ROIC in the substrate 410using a tin-silver alloy layer between the substrate 410 and thefeatures 40 and annealing at about 220° C.

In step 4017, the glass substrate 432 is released from the silicon oxidelayer 422 by illumination with UV light.

In step 4018, a heavily doped p type layer 435 is formed on the layer421 of the features 400 by a suitable technique such as ion implantationthrough the silicon oxide layer 422. The heavily doped p type layer 435can be annealed by laser to activate implanted dopant.

In step 4019, the silicon oxide layer 422 is removed by a suitabletechnique such as etching with HF.

In step 4020, an insulating material 433 is deposited by spin coating,evaporation or CVD to fill space between the features 400. Theinsulating material 433 preferably has a lower refractive index than thefeatures 400. The insulating material 433 can be any suitable materialsuch as silicon oxide and polyimide.

In step 4021, the insulating material 433 is planarized using a suitabletechnique such as chemical mechanical polishing (CMP) until the heavilydoped p type layer 432 of the features 400 is exposed.

In step 4022, a transparent conductive oxide (TCO) layer 434 isdeposited on the insulating material 433, using a suitable method suchas thermal evaporation, e-beam evaporation, and sputtering. The TCOlayer can comprise one or more suitable materials such as indium tinoxide, aluminum zinc oxide, zinc oxide, zinc indium oxide and graphene.

In step 4023, the insulating material 433 is optionally removed by asuitable method such as wet etching.

According to one embodiment as shown in FIG. 10, the device 10, 20, 30or 40 can be integrated with electronic circuitry into a polarizationdetector array. The electronic circuitry can include address decoders inboth directions of the detector array, a correlated double samplingcircuit (CDS), a signal processor, a multiplexor. The electroniccircuitry is functional to detect the electrical signal converted by thefeatures 100, 200, 300 or 400 from at least a portion of light impingedthereon. The electric circuitry can be further functional to calculatean interpolation of electrical signals from several subpixels, thefeatures on which extend in the same transverse direction. Otherfunction of the electronic circuitry can include a gain adjustment, acalculation of Stoke's parameters. In particular, the subpixels can bearranged into a group (i.e. pixel). For example, in FIG. 10, a subpixelA and subpixels B, C and D can be arranged adjacent to each other andreferred to as a pixel, wherein features on the subpixels B, C and Dextend in transverse directions at 45°, 90° and −45° relative to atransverse direction in which features on the subpixel A extend.

The device 10, 20, 30 or 40 can also be used as fore optics in a lightdetector apparatus as shown in the schematic in FIG. 11.

According to an embodiment as shown in FIG. 12, the features 100, 200,300 and 400 can each comprise a metal layer on each sidewall (i.e.surface extending in the transverse direction and the normal direction).The metal layer preferably has a thickness of about 5 nm to about 100nm, more preferably about 50 nm. The metal layer substantially coversthe entire sidewall and the metal layer does not extend to either end ofthe features in the normal direction.

The foregoing detailed description has set forth various embodiments ofthe devices and/or processes by the use of diagrams, flowcharts, and/orexamples. Insofar as such diagrams, flowcharts, and/or examples containone or more functions and/or operations, it will be understood by thosewithin the art that each function and/or operation within such diagrams,flowcharts, or examples can be implemented, individually and/orcollectively, by a wide range of hardware, software, firmware, orvirtually any combination thereof.

Those skilled in the art will recognize that it is common within the artto describe devices and/or processes in the fashion set forth herein,and thereafter use engineering practices to integrate such describeddevices and/or processes into data processing systems. That is, at leasta portion of the devices and/or processes described herein can beintegrated into a data processing system via a reasonable amount ofexperimentation.

The subject matter described herein sometimes illustrates differentcomponents contained within, or connected with, other components. It isto be understood that such depicted architectures are merely exemplary,and that in fact many other architectures can be implemented whichachieve the same functionality. In a conceptual sense, any arrangementof components to achieve the same functionality is effectively“associated” such that the desired functionality is achieved. Hence, anytwo components herein combined to achieve a particular functionality canbe seen as “associated with” each other such that the desiredfunctionality is achieved, irrespective of architectures or intermediatecomponents.

With respect to the use of substantially any plural and/or singularterms herein, those having skill in the art can translate from theplural to the singular and/or from the singular to the plural as isappropriate to the context and/or application. The varioussingular/plural permutations may be expressly set forth herein for sakeof clarity.

All references, including but not limited to patents, patentapplications, and non-patent literature are hereby incorporated byreference herein in their entirety.

While various aspects and embodiments have been disclosed herein, otheraspects and embodiments will be apparent to those skilled in the art.The various aspects and embodiments disclosed herein are for purposes ofillustration and are not intended to be limiting, with the true scopeand spirit being indicated by the following Claims.

What is claimed:
 1. A device operable to detect polarized lightcomprising: a substrate; a first subpixel; a second subpixel; a firstplurality of features in the first subpixel and a second plurality offeatures in the second subpixel, wherein the first plurality of featuresextend essentially in parallel in a first direction parallel to thesubstrate and the second plurality of features extend essentially inparallel in a second direction parallel to the substrate; wherein thefirst direction and the second direction are different; the firstplurality of features and the second plurality of features reactdifferently to the polarized light; wherein the first plurality offeatures comprises an electronic component, and wherein the electroniccomponent is functional to convert at least a portion of the polarizedlight to an electrical signal.
 2. The device of claim 1, wherein thepolarized light has linear polarization, circular or ellipticalpolarization.
 3. The device of claim 1, wherein the first plurality offeatures is equally spaced from each other.
 4. The device of claim 1,wherein space between features of the first plurality of features isfilled with a transparent material.
 5. The device of claim 1, whereinthe second subpixel is adjacent to the first subpixel.
 6. The device ofclaim 1, wherein the p-i-n diode is functional to convert at least aportion of the polarized light to an electrical signal.
 7. The device ofclaim 6, wherein the substrate comprises electrical componentsconfigured to detect the electrical signal.
 8. The device of claim 1,further comprising a first transparent electrode disposed on the firstsubpixel and electrically connected to each of the first plurality offeatures, and a second transparent electrode disposed on the secondsubpixel and electrically connected to each of the second plurality offeatures, wherein the first and second transparent electrodes areseparate.
 9. The device of claim 1, further comprising a reflectivematerial deposited on areas of the substrate between features of thefirst plurality of features.
 10. The device of claim 1, wherein each ofthe first plurality of features comprises an intrinsic semiconductorlayer or a first lightly doped semiconductor layer, and a heavily dopedsemiconductor layer; the substrate comprises a second lightly dopedsemiconductor layer; wherein the second lightly doped semiconductorlayer is an opposite type from the heavily doped semiconductor layer;intrinsic semiconductor layer or a first lightly doped semiconductorlayer is disposed on the second lightly doped semiconductor layer; andthe heavily doped semiconductor layer is disposed on the intrinsicsemiconductor layer or the first lightly doped semiconductor layer;wherein the heavily doped semiconductor layer, the intrinsic layer orthe first lightly doped semiconductor layer, and the heavily dopedsemiconductor layer form a p-i-n diode.
 11. A polarization detectorarray, comprising the device of claim 1 and electronic circuitryfunctional to detect an electrical signal.
 12. The polarization detectorarray of claim 11, wherein the electronic circuitry is furtherfunctional to calculate an interpolation of subpixels of the device,adjust a gain and/or calculate Stoke's parameters.
 13. The device ofclaim 1, wherein the first plurality of features or the second pluralityof features have a shape in a cross-section parallel to the substrateselected from the group consisting of a rectangle, an ellipse,convex-convex, concave-concave, plano-convex, and plano-concave.
 14. Thedevice of claim 1, further comprising a metal layer on each sidewall ofeach of the first plurality of features and the second plurality offeatures wherein the metal layer substantially covers the entiresidewall and the metal layer does not extend to either end of thefeatures in a direction perpendicular to the substrate.
 15. A deviceoperable to detect polarized light comprising: a substrate; a firstsubpixel; a second subpixel; a first plurality of features in the firstsubpixel and a second plurality of features in the second subpixel;wherein the first plurality of features and the second plurality offeatures react differently to the polarized light such that polarizationof polarized light is determined; wherein each of the first plurality offeatures comprises a p-i-n diode or forms a p-i-n diode with thesubstrate.
 16. The device of claim 15, wherein the first plurality offeatures are arranged in a different orientation than the secondplurality of features.
 17. The device of claim 15, wherein the featuresreact to polarized light by converting at least a portion thereof toelectrical signal.
 18. The device of claim 15, wherein the firstplurality of features and the second plurality of features aresubstantially shaped as blocks or prisms having a substantiallyrectangular shaped base, wherein the blocks or prisms protrude from asurface of the substantially rectangular shaped base.
 19. A method offabricating a device of claim 1; the method comprising: forming at leastone of the first plurality of features and the second plurality offeatures by conducting lithography, ion implantation, annealing,evaporation, atomic layer deposition, chemical vapor deposition, dryetch or a combination thereof.
 20. A method of fabricating a device ofclaim 15; the method comprising: conducting lithography, ionimplantation, annealing, evaporation, atomic layer deposition, chemicalvapor deposition, dry etch or a combination thereof.